In a digital still camera and a video camera employing CCD and CMOS, there are increasing demands for a compact zoom lens with a high variable-power ratio and a wide angle of view. Zoom lenses satisfying the aforesaid demands are disclosed in some Patent Documents. Each of these zoom lenses has five lens groups with a positive refractive power, a negative refractive power, a positive refractive power, a negative refractive power, and a positive refractive power in this order from the object side, and there is known a zoom lens in which variable-power ratio is about ×5 and an angle of view at a wide-angle end is about 76° (see Unexamined Japanese Patent Application Publication No. 2005-189670).
There is also known a zoom lens in which variable-power ratio is about ×50 and an angle of view at a wide-angle end is about 70° (see Unexamined Japanese Patent Application Publication No. 2001-33703).
In the aforesaid Patent Documents, the number of elements in the second lens group is four because all of four lenses in the second lens group are provided as single lenses, or the number of elements in the third lens group is three because four lenses in the third lens group are provided as two single lenses and one cemented lens. Accordingly, they cause relatively larger number of error contributing factors corresponding to lens interval and lens decentration, resulting in problems that accuracy control for lens assembly is complicated, and productivity is lowered.